Proximity detector
US4191894A · kind A · utility
11Cited by
4References
2Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 18, 1977 |
| Grant date | Mar 4, 1980 |
| Priority date | — |
| Expiry date | Nov 18, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2217/96075
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A proximity detector including a pair of antennae disposed at the front edge of a door with a space; and voltage converters for converting earth electrostatic capacities of the antennae to the corresponding voltages. The proximity detector further includes a first detecting circuit for detecting a differential signal of the outputs of the voltage converters; and a second detecting circuit for detecting a summing signal of the outputs of the voltage converters. The movement of the door is controlled by the output of the first detecting circuit and/or the output of the second detecting circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.